Security readout for executives and security teams
Plain-English summary
CVE-2026-1303 affects the MailChimp Campaigns WordPress plugin through version 3.2.4. A low-privileged logged-in user may disconnect the site from its MailChimp synchronization app. The main business impact is disruption to automated email campaigns and marketing integrations, not data theft or full site compromise based on the provided sources.
Executive priority
Prioritize within normal vulnerability management for affected marketing sites. Escalate if the site allows public registration or has many low-trust users, because campaign automation could be disrupted with little technical effort.
Technical view
The issue is a missing authorization check, CWE-862, in the mailchimp_campaigns_manager_disconnect_app function tied to a WordPress AJAX action. Sources state Subscriber-level authenticated users and above can trigger app disconnection. The CVSS vector in the bundle lists PR:N, which conflicts with the authenticated-user description, so privilege requirements should be validated against vendor/advisory details.
Likely exposure
Exposure is limited to WordPress sites running MailChimp Campaigns up to and including 3.2.4, especially sites allowing Subscriber accounts or public user registration. Sites not using this plugin, not connected to MailChimp, or without untrusted authenticated users face lower practical risk.
Exploitation context
No source in the bundle reports active exploitation, and KEV is false. Exploitation requires reaching the affected WordPress AJAX action and, per the description, having at least Subscriber-level access. The likely outcome is unauthorized disconnection from MailChimp synchronization, causing operational disruption.
Researcher notes
The provided sources identify the vulnerable function and WordPress Trac line references. No fixed version or vendor mitigation is named in the bundle. The CVSS privilege field appears inconsistent with the narrative, so researchers should confirm authorization behavior in a non-production test environment without attempting weaponization.
Mitigation direction
- Identify WordPress sites running MailChimp Campaigns and record installed versions.
- If running version 3.2.4 or earlier, check vendor or WordPress plugin guidance for an updated release.
- Limit untrusted Subscriber-level accounts until remediation is confirmed.
- Consider disabling the plugin if MailChimp campaign synchronization is not business-critical.
- Monitor MailChimp integration status for unexpected disconnections.
Validation and detection
- Check plugin inventory for olalaweb-mailchimp-campaign-manager or MailChimp Campaigns installations.
- Confirm whether installed versions are 3.2.4 or earlier.
- Review WordPress users with Subscriber or higher roles for untrusted accounts.
- Verify whether MailChimp synchronization remains connected after user activity.
- Review application logs for unexpected calls to the disconnect AJAX action.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-862: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-1303 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N3.91.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/threat-intel/vulnerabilities/id/c2057ec2-9f03-4ae9-b200-aa5a318b461e?source=cveCVE reference
- https://plugins.trac.wordpress.org/browser/olalaweb-mailchimp-campaign-manager/trunk/mailchimp-campaigns-manager.php#L636CVE reference
- https://plugins.trac.wordpress.org/browser/olalaweb-mailchimp-campaign-manager/tags/3.2.4/mailchimp-campaigns-manager.php#L636CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Missing Authorization
Missing Authorization represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.